#include "udf.h" #include "dpm.h" #include "surf.h" #define C1 0.00000000000000000000004 #define C2 0.00000000002 #define C3 0.000000000000005 DEFINE_DPM_BODY_FORCE(p_b_force,p,i) { real conc; real bforce; real acc; cell_t c=RP_CELL(&(p->cCell)); Thread *t=RP_THREAD(&(p->cCell)); if(i==1) acc=0.0; else if(i==0) {conc = C_STORAGE_R(c,t,SV_DPMS_CONCENTRATION); bforce=(C1*conc*P_POS(p)[0]*P_POS(p)[0]/P_MASS(p)+C2*P_POS(p)[0]+C3/(P_POS(p)[0]*P_POS(p)[0])); acc=bforce/P_MASS(p); } return (acc); } I want to know whether does it forced on every particle in the gas flow field or it just forced on injection particles in the injecting inlet? If so, How to add the loops in the UDF and give the force on every particle in the flow field but not the injecting inlet? Thank you so much!!